Automatic collet chuck



Oct. 3, 1944. c B'ELL 2,359,507

AUTOMATIC COLLET CHUCK Filed March 29. 1943 3 Sheets-Sheet 1 INVENTOR,

CURTIS M. BELL.

Oct. 3, 1944. c. M. BELL AUTOMATIC COLLET CHUCK Filed March 29, 1943 zSheets-Sheet 2 INVENTOR, CUR T/S M. BELL.

ATTQRNEY.

Oct. 3, 1944. c. M. BELL 2,359,507

AUTOMATIC COLLET cnucx Filed March 29 1.945 3 Sheets-Sheet 3 INVENTOR,CURTIS M. 'BELL.

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A T TORNEK Patented Oct. 3, 1944 UNITED STATES PATENT OFFIE 2,359,507AUTSMAT'IC COLLET CHUCK Curtis M. an, Berkeley, Calif.

' Application March 29, 1943, s eiial-Ndl- 480,919

7 Claims; (01. 279-59) The present invention relates to chucks andparticularly to'a collet chuck which can bereleased or' engaged Withoutstopping the lathe; It is in' the nature of an improvement over mycopending application for fA'utomatic collet chuck, serial Number409,875; filed September 6, 1941. l

The invention is adapted for use in coi'ijun'c tion with standardrotating machines, such as lathes, drillpresses, milling machines, jigborers, and the like.

My chuck maybe afi'iXed to a standard type of rotating machine byscrewing or otherwise affixing the spindle DIate' thereof to the chuck.By thus affixing my novel chuck to such a standard machine, said machineis' immediately transformed into an automatic high-speed productivemachine capable of continuity of high-speed production.

Objects of my invention are generally to improve and increase the speedand economy of the operation of lathes and like rotating machine; toprovide an automatic collet chuck which issim'ple tomanufacture'andassemble and likewise to disassemble and repair; toprovide a greater gripping leverage than has heretofore been known withthe same amount of power; to provide an automatic collet chuck readilyadapted'ior use with standard'rotatingmachineryj and another object isto provide a simple and'eifctive braking mechanism for use inconjunction with automatic collet chucks. Other objects and'advantageswill become apparentto those skilled in the art from the disclosure ofmy invention and the drawings and'specification forminga part of theapplication.

Referring to the drawings in which similar characters of referencerepresent corresponding parts in the several views:

v Fig; liis an end elevation of my invention as seen from' thegendopposite'the" collet, andshowin g'fj the spindle section.

Fig. 2 is a longitudinal sectional view of my invention, taken on line2-2" of Fig-l, showing the collet in work-releasing position Fig. 3 is atransverse sectional view of my hub assembly, taken on line 33'of' Fig.2;

' {have provided a device utilizing very few moving" parts for the rapidrelease or gripping spindle-plate I; which in turn is suitably attachedto a spindle 8. V v

The spindle plate! is; made fast to the rear head' by means of equallyspaced machine bolts 9;. Front head 4, rear head 5', and spindle plate 1are joined together by equally spaced machine bolts Ill-Q I prefer toprovide dowels II in aligned bores l2" provided in: the two: headsinorder to properly and accurately align" and orient the assembly, a

ront head 4 and rear head 5 each carry, respectively, brake drums l5 andI6 rotatably mounted thereon and which travel respectively on-b'allbearing races' l1 and I8. The brake drums l5 and iii are each formedwith outer peripheral notches l9 and 20 for the reception of awake shoeas will hereinafter appear. Inher bevel gears 2l a'nd 22 are providedin' brake drums 5 arm re, respectively.

Thebevel gears and 22 are adapted to mesh withedually spaced bevel gearshafts generally indicated at I have shown three bevel gear shaftsspaced from one-another in balanced relation; Each of the said bevelgear shafts comprises a crown" bevelgear portion 24', which meshes withthe bevel g'ear's 2| and 22, a shaft portion 25 carrying a split brassbushing 2'6',' an inner gearp'ortion' 2 1 and terminal bearing 21a.

Inner bevel gea 2-1 is adapted to mesh withdraw n'ut 28formed' with abevel gear 29.- The said draw nutis positioned circumferentially ofcollet 2", in recess 30" formed in the inner portion of the frontheadvll opposite the nose portion of said head. The draw nut 28 isprovided with an internal thread 3| which engages right hand thread 32formed in said collet 2. A ball bearing race 334s provided in the'saidrecess 30 offront head 4 so that" the said draw nut 28 may rotate easilyrelative to said head.

The nose portion of my front head 4 is provided with a hardened steelbushing 35'. It is noted that Fig. 2 illustrates the collet indistended,;un-lock'ed position.- c

I prefer to provide aguide pin 38'tapped in front head 4 in any suitablemanner; which projects into longitudinal groove 39: formed in collet- 2inorder to key the' said collet properlyv and prevent rotation'thereof'relative to front head 4,; but allow axial movement of the colletrelative to the said head.

My braking mechanism utilizes but a single control lever 45. Brake shoes46 and 41" are supported on brake rods 48 and 49 respectively;vertically journaled in a housingmember 50 attached to the lathe bed inany suitable manner.

Levers 5|.and 52 extend from control lever 45 into engagement with brakerods 48 and 49.

It is here noted that in normal working oper ation, all parts includingthe drums, bevel gear shafts, draw nut, and collet, rotate around thelongitudinal axis of the assembly according to the rotation of the hub 3driven by the spindle. lift is only when one of the drums is retardedthat there is a relative rotation between the parts caused by the bevelgear shafts turning on their own axes. The bevelgear shafts 28 remainidle and do not rotate on their own axes until one of the drums isretarded and then only is there a relative rotation between the partscaused by the bevel gear shafts turning on own axes in a clockwisedirection by meshing with the teeth of the said retarded drum and hencewill drive draw nut gear 28 in the opposite or clockwise directionrelative to the rotating, hub, spindle, and collet and hence screw up onthe right hand thread formed in collet 2 and cause gripping of the workstock. Conversely,

if drum I6 is retarded, draw nut gear 28will be driven in a clockwisedirection, hence causing the draw nut 28 to unscrew from, right handthreaded collet 2 and release the work.

Referring to the braking action, if lever 45 is rocked on its pivotalmounting 53 to the right, as shown in full line position 54, rod 48 willforce brake shoe 46 into the notch l9 and into engagement with drum I5causing the collet to grip work therein. If the lever 45 is moved to theright, as shown in dotted position 55, rod will force shoe 4'! againstdrum I6 and thereby cause the collet to release work therein.

V I1; is obvious that other braking mechanisms may be utilized than thatdescribed specifically herein.

While the invention has been illustrated and ,described in certaindetail of embodiment for illustrative purposes, it is not intended thatthe invention be limited thereto but that modifications and changes indetails of construction may be incorporated within the spirit and scopeof the appended claims.

I claim:

1. An automatic collet chuck adapted for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said rotating machine, comprising ahub for attachment to a spindle, a collet fixed 'non-rotatively in saidhub and movable axially thereof to grip and re: lease stock, separatelymovable brake drums mounted about, and rotatable relative to, said hub,differential gearing within said hub actuated by relative rotation ofsaid drums to trav- 'erse said collet axially of'said'hub, saiddifferential gearing including a plurality of spaced bevel gear shaftsmounted for free rotation and positioned to mesh with said brake drumand a 2. An automatic collet chuck adapted for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said rotating machine, comprising atwo-part hub arranged for attachment to a head spindle, a non-rotatablecollet axially movable within said hub for releasing and gripping stockto be machined, brake drums rotatably mounted on said hub and rotatablewith respect to one another and said hub, bevel gear shafts positionedbetween the said two parts of said hub, said bevel gear shafts mountedfor free rotation and positioned to mesh with said brake drums and adraw nut threadably engaged with'said collet.

3. An automatic collet chuck adapted for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said rotating machine, comprising ahub for attachment to a spindle, a collet fixed non-rotatively in saidhub and movable axially thereof to grip and release stock, separately,movable brake drums mounted about, and rotatable relative to, said hub,differential gearing within said hub actuated by relative rotation ofsaid drums to traverse said collet axially of said hub, saiddifferential gearing including a plurality of freely rotatable spacedbevel gear shafts positioned to mesh with said brake drums and a tootheddraw nut threadably engaged with said collet, brake means selectivelyoperable against said drums comprising a mounting member, brake rodsslidably disposed in said mounting member, brake shoes fixed to saidrods, a control lever, and

- means for moving said rods by said handle to' engage said shoesalternatively with said drums.

4. An automatic collet chuck adapted for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said rotating machine, comprising atwo-part hub arranged for attachment to a head spindle, a non rotatablecollet axially movable within said hub for releasing and gripping stockto be machined,

' brake drums rotatably mounted on said hub and rotatable with respectto one another and said hub, bevel gear shafts positioned for free, rotation between the said two parts of said'hub, said bevel gears shaftsmounted for free rotation and positioned to mesh with said brake drumsand a draw nut threadably engaged with said collet, brake meansselectively operable against said and means for moving said rods by saidhandle to engage said shoes alternatively with said drums.

5. An automatic collet chuck adapted for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said 'rotating machine, comprisinga two-part hub ,ar-

ranged for attachment to a head spindle, a nonrotatable collet axiallymovable within said hub for releasing and gripping stock to be machined,

a pair of internally toothed brake drums mounted for free rotation onsaid hub, bevel gear shafts mounted for free rotation and positionedbetween said hub portions and comprising a crown bevel gear portion,shaft portion, and inner bevel gear portion, and. an exteriorlytootheddraw nut threadably engaged with said collet, said crown bevelgear portion arranged to meshwith said toothed brak drums, said innerbevel gear portion arranged to mesh with said toothed draw nut.

6. An automatic collet chuck adapted. for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said rotating machine, comprising atwo-part hub arranged for attachment to a head spindle, a nonrotatablecollet axially movable within said hub for releasing and gripping stockto be machined, a pair of internally toothed brake drums mounted forfree rotation on said hub, bevel gear shafts mounted for free rotationand positioned between said hub portions and comprising a crown bevelgear portion, shaft portion, and inner bevel gear portion, an exteriorlytoothed draw nut threadably engaged with said collet, said crown bevelgear portion arranged to mesh with said toothed brake drums, said innerbevel gear portion arranged to mesh with said toothed draw nut, andbraking means adapted to selectively retard a brake drum, said brakingmechanism utilizing but a single control lever.

7. An automatic collet chuck adapted for connection to a standardrotating machine such as a lathe and operable to selectively release orengage work stock during rotation of said rotating machine, comprising ahub member arranged for attachment to a spindle, a collet axiallymovable Within said hub for releasing and gripping stock to be machined,brake drums mounted for free rotation on said hub, means to impartrelative rotation between said collet and a draw nut threadably engagedtherewith including difierential gearing arranged to mesh with saidbrake drums and said draw nut, said means operable during rotation ofsaid hub, and means to selectively retard one of said drums.

CURTIS M. BELL.

